In this lab you will learn about properties of liquids, specifically cohesion. This paper provides an example of an innovative science teaching applied in an introductory chemistry course for future elementary teachers at a small university in northeastern turkey. Larger molecules are more polarizable than smaller molecules since. Experiment 12z intermolecular forces and the liquidvapor. We used london dispersion forces, dipoledipole forces, and hydrogen bonding. Imfs are the forces that keep multiple molecules together. The polar molecule induces a temporary dipole in the nonpolar molecule. They are not to be mistaken with intramolecular forces, which are the forces between atoms inside the molecule itself. In this lab, you will design a procedure to analyze intermolecular forces in isopropyl. By the end of this unit students should be able to the london dispersion force is the weakest intermolecular force. Without intermolecular forces holding molecules together we would not exist. Read and learn for free about the following article. Intramolecular and intermolecular forces if youre seeing this message, it means were having trouble loading external resources on our website. Both types of forces determine the chemical and physical characteristics of substances.
Students will learn about intermolecular forces by becoming lava lamp fanatics. These forces control the movement of molecules and atoms. In the first part of this lab, you will build molecular models of maleic acid and fumaric acid to aid in the understanding of the inter and intramolecular forces present. Acetone evaporated first, followed by alcohol and water. This fully editable lab station on types of bonds and intermolecular forces is meant to get your students out of their seats and engaged in the content. The most significant intermolecular force for this substance would be dispersion forces. Nord, eastern michigan university with large parts adapted from chemistry with computers by dan d. Intermolecular forces moleculesatoms can stick to each other.
Acs guidelines and recommendations for teaching middle and high school chemistry 3 introduction one of the goals of the american chemical society acs is to support excellence in education by fostering the development of innovative, relevant, and effective chemistry and chemistryrelated education. The forces between molecules that hold molecules together are called intermolecular forces imf and are comprised of. Examples of intermolecular forces are london dispersion forces ldf, dipoledipole forces ddf, and hydrogen bridging forces hbf. Compare some physical properties of water with those of other liquids. In contrast, intramolecular forces act within molecules intermolecular forces are weaker than intramolecular forces. Predict the molecular shape of each of the following. Intermolecular forces imfs are attractive interactions between molecules.
Intramolecular forces are forces acting on atoms within ionic crystals or molecules. Students attempt to place drops of various types of liquids on the face of a penny or any available coin. Make a data table and graph in excel for the effect of intermolecular forces on pressure. Lab intermolecular forces zumdahl cd std 2 chapter assignment. Select intermolecular forces from the window that comes up 4. The purpose of this experiment is to measure the effect of temperature on the vapor pressure of several liquids. I can classify the type of intermolecular forces hydrogen bonding, dipoledipole interaction, and london dispersion forces present in covalent molecules. Forces the chemical bonds within an individual molecule. When those forces are between like molecules, they are referred to as cohesive forces. Title intermolecular forces and states of matter interactive lecture demonstration. Intermolecular forces lab intermolecular forces are forces that act between molecules rather than interamolecular forces which act within a molecule.
Intermolecular forces are the attractive forces holding particles together in the condensed. We will examine connections between molecular structure, intermolecular forces, and physical properties. Droplet of water on a solid surface shows how liquid molecules stick together. Introduction description this is a perennial favorite for students young and old which provides an excellent visual example of the strength of intermolecular attractions. Volz purpose the purpose of this experiment is to explore the relationships between molecular size, composition, and intermolecular forces. The intermolecular forces forces between molecules are weaker than intramolecular. Strong imfs lead to high boiling points, low vapor pressures, and high heats of vaporization. Intramolecular forces are responsible for many macroscopic properties such as electrical conductivity, hardness, and luster. Intermolecular attractive forces hold molecules together in the liquid state. You might not require more get older to spend to go to the books introduction as well as search for them. Librivox is home to thousands of free audiobooks, including classics and outofprint books. Although this molecule does not experience hydrogen bonding, the lewis electron dot diagram and vsepr indicate that it is bent, so it has a permanent dipole. The stronger the intermolecular forces between the molecules of a liquid, the greater the energy required to separate the molecules and turn them into gas a higher boiling point trends. This charge is permanent in nature, and it is caused by either an excess of electrons in anions or protons in cations.
Lab intermolecular forces zumdahl cd std 2 chapter london dipole hydrogen bonds 1. A study of the intermolecular forces in candy dye molecules. Types of forces london dispersion forces induced dipoleinduced dipole forces. Ions, dipoles, and polarizability concept overview. Intermolecular forces information intermolecular forces are the interactions between rather than inside molecules. The aim of this sciencestruck post is to put forth the concept of how different intermolecular forces work along with some examples for a better understanding of the concept. The aim of the lesson is to help prospective elementary teachers understand the intermolecular forces in a simple way and see an innovative teaching example.
While ionic and covalent bonds form between atoms, intermolecular forces or intermolecular attractions hold molecules. The temperature where the substance becomes liquid and where it becomes solid. In part ii, the objective is to measure the enthalpy of vaporization for four organic compounds and describe the intermolecular bonding energy. Each station not only offers a unique opportunity to test your students knowledge offer an opinion, answer questions based on a. Intermolecular forces of attraction and chromatography. The first brought things together while the second caused them to part. They are responsible for many of the physical properties of substances, including their melting and boiling points. The main difference between intermolecular and intramolecular forces is that. Students know atoms combine to form molecules by sharing electrons to form. Comparing intermolecular forces important background information for lab and test preparation. Intermolecular forces are produced through the formation of dipoledipole bonds, hydrogen bonds, or london forces. The properties of matter result from the properties of the individual molecule resulting from chemical bonding and how the molecules act collectively resulting from intermolecular forces. They lead to differences and sometimes trends in various physical properties.
View notes chem 162 lab 3 from chem 162 at university of washington. Pdf on jan 1, 2016, kara paden and others published sweet chemistry. For the virtual lab, record in a procedure to determine. The stronger the attractive forces between the particles, the more they resist moving.
This experiment was performed in order to acquaint students the importance of intermolecular forces and how they are applied to consumer products such as chapstick or lipstick. The london dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles. This lesson will introduce the three main types of intermolecular forces london dispersion, dipoledipole, and hydrogen bonding, and distinguish them from intramolecular forces. I have a lab due tomorrow and didnt understand the concepts and data well so answering questions was hard. A simple explanation of intermolecular forces with.
Pdf teaching intermolecular forces with love analogy. Never confuse hydrogen bonding with a bonded hydrogen. Bookmark file pdf intermolecular forces lab and answers intermolecular forces lab and answers this is likewise one of the factors by obtaining the soft documents of this intermolecular forces lab and answers by online. How can i recognize the type of intermolecular force. Chapter 12 intermolecular first page of chapter forces and. Do the problems on your own before looking at the answers.
In part i, you will use the melting point apparatus to determine the melting point of each of the two substances labeled sample a and sample b. Students will be working in groups of four and will be conducting three separate activities to explore the intermolecular forces described in the video. Jan 15, 2017 intermolecular and intramolecular forces are the two types of forces that hold individual molecules and atoms together. These experiments show the differences in surface tension, evaporation. In todays lab we will examine the attractive forces that hold molecules together and the disruptive forces that break them apart. There are only three states, but there can be many phases e. The objective of part i is to understand the effect of intermolecular and intramolecular forces on melting points and acid dissociation constants. My questions on chemistry lab data intermolecular forces. The biggest difference between bonds and imfs is the imf are much weaker than the bonds. If youre behind a web filter, please make sure that the domains. Terminologies intermolecular forces of attraction a force of attraction between molecules dipoledipole stronger than london dispersion. Combine all of this and you get the bragg equation named after william henry bragg and his son. The decrease in mass is related to the strength of the intermolecular forces of attraction. The table below compares the strength of various intermoelcular forces.
C is a polar compound with dipoledipole intermolecular forces there is a lone pair on the phosphorus. Following each lewis structure, indicate london forces by l, dipoledipole by d and hydrogen bonding by h. Difference between intermolecular and intramolecular forces. Pyrex, a borosilicate glass lab ware is made when b2o3. Description this interactive lecture demonstration has the following learning goals students will be able to. A, as a larger molecule, will have stronger intermolecular forces than b. Intermolecular and interatomic forces intermolecular forces. If the first station is busy when you begin, feel free to. You will also recall from the previous chapter, that we can describe molecules as being either polar or nonpolar. List all types of imfs that would occur in each of the following you should have a good. Mar 25, 2020 it should be made clear that intermolecular forces will always be weaker than the intramolecular forces ionic, covalent, or metallic bonding in a particular substance. Intermolecular forces 1 intermolecular forces imfs a the attraction between molecules that are responsible for a substances state of matter b the stronger the imf the higher the melting point of a solid, the higher the boiling point of the liquid, the stronger the surface tension, the stronger the cohesive and adhesive forces.
Water, having a formula of h 2 o is a polar molecule able to create hydrogen bonds and dipoledipole bonds with other molecules. Experiment 12z intermolecular forces and the liquid. The ability to use representations of molecular structure to predict the macroscopic properties of a substance is central to the development of a robust understanding of chemistry. Be sure to emphasize that hydrogen bonding is an intermolecular force, not a bondan intramolecular force, like ionic, covalent, or metallic bonds. Intermolecular forces forces of attraction and repulsion between molecules that hold molecules, ions, and atoms together. Celebrating prezi s teacher community for teacher appreciation week. In comparison with ionic and covalent bonds those forces are very weak. Oct 17, 2014 intermolecular forces of attraction lab report 1. The size of a molecule can affect the london dispersion force between two molecules. At no point in this activity do i mention a single imf, discuss molecular structure, or deal with polarity. Co2 covalent h2o covalent nh3 covalent ch4 covalent detail 2 detail 3 3state whether. This activity illustrates the effect of intermolecular forces on surface tension of a liquid.
Intramolecular forces of chemical bonds within a molecule boiling point and electronegativity boiling point the temperature at which the liquid form of a compound vaporizes into a gas. While intermolecular forces are strong enough to keep molecules together in the solid and liquid state, they are not nearly as strong as covalent bonds. This lab will explore changing masses during evaporation of organic liquids. Intermolecular forces are forces of attraction between molecules that. List the 3 main types of intermolecular forces that were explored in todays lab. The force of the attraction is inversely related to the square of the distance between the charges. A polar molecule is one in which there is a difference in electronegativity between the atoms in. Intermolecular forces are forces that act between molecules rather than interamolecular forces which act within a molecule.
Intermolecular forces of attraction bautista, laureenkate capistrano, amiel espiel, kyle nicolas, ezber 2. Types of bonds and intermolecular forces 7 engaging lab. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Intermolecular forces, or imfs, are the attractive forces between molecules. List one difference between an intermolecular force and a bond. Intermolecular forces are required to make molecules stick together, and they are the reason why compounds with differing chemical properties have different physical properties. Intermolecular forces lab student report clarke chemistry. Melanie stewart, stowmunroe falls high school, stow, oh 44224 i.
Chem 162 lab 3 name alice mengju hsieh quiz section. Intermolecular and ionic forces gcc, 20 page 4 of 12 intermolecular and ionic forces compar ing imf using percent evaporation. This molecule has an h atom bonded to an o atom, so it will experience hydrogen bonding. If the molecules have very different molar masses by a factor of 2 or. Intramolecular and intermolecular forces article khan academy. Intermolecular forces of various substances lab report. Stronger intermolecular forces molecules are more attracted to each other they stick together better they are harder to separate from each other.
Note that the terms state and phase are not interchangeable. A and b are hydrocarbons with dispersion intermolecular forces. A change between these states is called a phase change or phase transition. You will move from one station to another to do the different sections of the lab. In chemistry 101, you learned that ions are simply molecules possessing a chargeanions are negatively charged, and cations are positively charged. A drop of each sample was placed on the table to determine which one evaporates first at room temperature. Types of intermolecular forces with video tutorials and quizzes, using our many waystm approach from multiple teachers. Dependent on the magnitude of the charge dependent on distance between charges.
Further, as it requires energy to vaporize a liquid, faster. A new page will appear showing your correct and incorrect responses. Weaker than forces of ionic bonding involve partial charges. Larger molecules are more polarizable than smaller molecules since they contain more electrons. Physical properties such as solubility, melting point, and boiling point are determined by a substances intermolecular forces. It is not necessary to do the different sections in order. The students have little understanding of these concepts because this activity was designed to generate questions they will attempt to answer through their study of the. Experiment 1 intermolecular forces of attraction 1. Effect of intermolecular forces on boiling point and. When you have completed every question that you desire, click the mark test button after the last exercise. Experiment 10 5 november 2019 intermolecular forces. Intermolecular forces magic tricks demonstrates magical properties of some common materials.
The purpose of the experiment is to determine the strength of intermolecular forces within alcohol, acetone, and liquid water. The strength of the attractive forces depends on the kinds of particles. The vapor pressure depends on the temperature of the sample since a higher temperature gives a larger fraction of highenergy molecules, and on the strength of the intermolecular forces holding molecules of the. In pure substances, there are 3 important intermolecular forces which may be present. However, if the nonpolar molecules species with strong intermolecular forces are more difficult to convert from liquids into gases. Intermolecular forces are forces that act between molecules. Molecules liquid state experience strong intermolecular attractive forces. I can infer the relative strength of intermolecular forces based on observations of physical properties. What is chemically special about each type of intermolecular force. The strength of the attractions between particles of a substance determines its physical state.
Physical properties for example as melting point or boiling point are mainly a result of such intermolecular forces. Different solvents were used to test the intermolecular forces of the. Introduction to phase changes and intermolecular forces there are three states of matter. Determining intermolecular forces through analysis of evaporation rates of solvents. Attractive forces particles are attracted to each other by electrostatic forces. However, they can play a crucial role in chemistry and biochemistry. Those should be stronger than the intermolecular forces in both. Comparing the strength of intermolecular forces lab. Lab report 1 intermolecular forces sample objective.
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